To the Editor.—The reply by McGuffin et al1 to our letter concerning their use of our diagnostic criteria for schizophrenia contains factual errors that we would like to correct.McGuffin et al have stated the following: "They [Abrams and Taylor] compounded their confusion of basic concepts by frequently using the term 'genetic' when they meant 'familial.' "The opening sentence of our article reads as follows: "There are two reasons for reassessing genetic (more accurately, familial) transmission in schizophrenia.... "2McGuffin et al commented that: "[Abrams and Taylor] have misled both themselves and their readers by stating that the 1978 criteria are a 'slightly broadened' version of their 1975 criteria."Applying our 1974 criteria to a sample of consecutive admissions to an acute-treatment psychiatric unit of a municipal hospital identified 4.5% as schizophrenic.3 Applying our 1978 criteria to a sample of consecutive patients admitted to an acute-treatment university